A Boost for Biodiversity

A park ought to protect habitat, but some conservationists have suggested that parklands aren't any more pristine than neighboring areas. Now a study shows that parks do, in fact, preserve biodiversity and protect land from damage associated with agriculture, hunting, logging, fire, and grazing. The finding suggests that parks should remain a key focus of conservation strategies.

The tropics are some of the most biologically rich areas in the world. Although many tropical countries have established parks in the last few decades, the efficacy of such set-asides has been questioned. "The word on the street was that tropical parks are paper parks, parks in name only, with no resources and overrun by settlers," says study co-author Raymond Gullison, a forest ecologist at the University of British Columbia in Vancouver, Canada.

To test whether tropical parks perform better than their reputation, Gullison and colleagues from Conservation International in Washington, D.C., surveyed park managers, scientists, and nongovernmental organizations working in 93 protected areas in 22 tropical countries. All respondents were promised anonymity for themselves and their parks. The researchers focused on parks that were under significant pressure from human uses of adjacent lands. In addition, the parks had to prohibit logging and other consumptive uses, contain at least 5000 hectares, and have existed for at least 5 years.

The parks seem to be holding up well. Rather than turning into farms, 83% of the parks had maintained or increased their natural vegetation. Compared to surrounding areas, 80% of the parks suffered less clearing, logging, and fire damage, and 60% had less hunting and grazing damage. The critical factor was the density of park guards. It was eight times higher in the 15 most effective parks than in the 15 least effective parks. Catching violators and administering penalties also correlated with successful protection, the researchers report in the 5 January issue of Science.

To experts, the point is clear. "What they really demonstrated, I think for the first time, is that law enforcement and active protection of parks really works," says Carel van Schaik, a tropical ecologist at Duke University in Durham, North Carolina.